document.write( "Question 1030968: Level 3: Three teachers have provided you with an equation that models their salaries in million of dollars each year. \r
\n" ); document.write( "\n" ); document.write( "Teacher A: A(x) = 4x + 50\r
\n" ); document.write( "\n" ); document.write( "Teacher B: B(x) = 2x2 + 31\r
\n" ); document.write( "\n" ); document.write( "Teacher C: W(x) = 2x - 5\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "During which years does Teacher A make the most money? Between what two years?
\n" ); document.write( "

Algebra.Com's Answer #645874 by LinnW(1048)\"\" \"About 
You can put this solution on YOUR website!
Teacher A: A(x) = 4x + 50
\n" ); document.write( "Teacher B: B(x) = 2x2 + 31
\n" ); document.write( "Teacher C: W(x) = 2x - 5
\n" ); document.write( "Teacher A will always make more than Teacher C,
\n" ); document.write( "So let's first see when the salary for A and B are
\n" ); document.write( "equal.
\n" ); document.write( "\"4x+%2B+50+=+2x%5E2+%2B+31\"
\n" ); document.write( "add -4x -50 to each side
\n" ); document.write( "0 = 2x^2 - 4x - 19
\n" ); document.write( "The quadratic formula provides the following solutions
\n" ); document.write( "\"1-sqrt%2821%2F2%29\" and \"1%2Bsqrt%2821%2F2%29\"
\n" ); document.write( "\"1-sqrt%2821%2F2%29\" is negative, so the root of interest
\n" ); document.write( "is \"1%2Bsqrt%2821%2F2%29\" which is approximately 4.24
\n" ); document.write( "From this we can say that in year 5 Teacher A
\n" ); document.write( "will make more than Teacher B. This will also
\n" ); document.write( "be true for years beyond 5
\n" ); document.write( "
\n" );